Share your knowledge on these two classic MPCs
By Acid Mitch Fri Apr 05, 2013 8:09 am
So I got one of those USB inverters from Ebay.

In the MPC Bible thread Micb States
"Use your original power lead (the one that feeds the original inverter board), just chop it in half and then chop the usb head off the new inverter and solder together. The same for the backlight connection, chop off the connector head on the backlight, and the new inverter, and solder wires together."

When I chopped the USB head off the new inverter it revealed 2 wires and a ground.
Does it matter which wires I solder together when connecting the power cable to inverter and inverter to Backlight cable ?

My multimeter has died on me so I cant test atm.
By micb Sat Apr 06, 2013 9:56 am
So how many wires you have in your usb all together 3? If so what colors are they?

Which inverter did you actually buy? Show us a link. All the ones I have played with have just had 2 wires, a positive and negative. (red and black).

It does matter which way round you get the feed to the inverter, but the output side which connects to the backlight doesn't matter.
By Acid Mitch Sat Apr 06, 2013 12:15 pm
micb wrote: So how many wires you have in your usb all together 3? If so what colors are they?
..


There's a black,red and what looks like a ground on the USB side.
The other side ihas 2 black.

micb wrote:Which inverter did you actually buy? Show us a link. All the ones I have played with have just had 2 wires, a positive and negative. (red and black).
.


http://www.ebay.co.uk/itm/USB-5V-DC-to- ... 35c54930b8


micb wrote:It does matter which way round you get the feed to the inverter, but the output side which connects to the backlight doesn't matter.


Cool, thanks.
By Clint Sat Apr 06, 2013 1:11 pm
Clint wrote:
Image


SimonInAustralia wrote:The original MPC60 and MPC3000 inverters seem to output somewhere around 95 VAC at 500-550 Hz...This replacement says it outputs 233 VAC at 4.2 kHz.


Having made some enquiries about this USB invertor with people who know about these things including Matt (saint_baz) who supplies my EL foils, I'd have to say that while the USB invertor is cheap, works silently and gives a backlight which is much brighter compared to the original part, you should note the following.

Consider the OUTPUT VOLTAGE, which is more than DOUBLE that of the original part. Think of the damage and risks that could potentially be caused by this voltage hike in the medium/long-term.
By micb Sat Apr 06, 2013 2:00 pm
The one which we actually should be using is this one
http://www.ebay.co.uk/itm/12V-DC-to-AC- ... 4d0a594a6d

This at 5v is alot closer to the original output voltage. This at 6v gives out 77v, which is alot lower than 240v. It is a little bit bigger, but is alot closer when compared to the original spec. Maybe clint could alter the link in the 60 bible with this inverter instead.

I hadn't got round to speaking to clint on this issue yet, but the one which I originally listed gives out a fair amount higher output voltage than the original.
By Clint Sat Apr 06, 2013 4:12 pm
I can remove the links to the 'suspect' hi-voltage invertor. If you want to repost with a more appropriate link go ahead. Would probably help if some evidence was provided as to the effectiveness of the low-voltage invertor. Does putting out a lower voltage than the original mean the screen is less bright? Is the lower voltage completely safe to recommend to a worldwide audience of 60 users? Install photos?
By micb Sat Apr 06, 2013 4:23 pm
Well lower voltage is better than higher voltage from a safety aspect so what would be the problem of recommending that?

I have installed the lower voltage inverter and it is pretty damn good. I haven't done a side by side comparison with a standard inverter, so I don't have pics. But I have one of them fitted in my machine and it looks dope. Still pretty damn bright. Will post some up soon.
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By SimonInAustralia Sat Apr 06, 2013 6:33 pm
Clint wrote:Consider the OUTPUT VOLTAGE, which is more than DOUBLE that of the original part. Think of the damage and risks that could potentially be caused by this voltage hike in the medium/long-term.

I don't think that the higher inverter output voltage would be a problem, as it is only connected to the backlight.

The backlight 'might' put out more heat, due to the higher brightness/voltage/etc., but no idea if that would cause any long term issues.

If there were to be any long term problems, it would possibly only be due to a possible higher current draw on the 5V output of the power supply. You would have to test the power lines to the original and replacement inverters with an ammeter/multimeter to know what the difference is, and have some electronic engineering skills to determine if any difference found would be harmful to the power supply.

Other issues might be a difference in noise from the inverter into the audio path, due to different voltages and frequency.


Clint wrote:Does putting out a lower voltage than the original mean the screen is less bright?

The difference in frequency of the AC voltage might also make a difference to backlight brightness.

It puts out a lower AC voltage than the original inverter, but the frequency of that AC voltage is 5-6 times more than the original, so maybe that makes up for the lower voltage?
By micb Sat Apr 06, 2013 9:57 pm
SimonInAustralia wrote:Other issues might be a difference in noise from the inverter into the audio path, due to different voltages and frequency.


That is a fair point, but luckily on the 2 of these I have tested, they seem to be grounded really well, and there is no leak back into the audio signal outputs,which is nice.
By Clint Sun Apr 07, 2013 8:13 pm
Can't be too careful with these old machines, just glad we are able to keep them alive and working great. Who needs vintage mode...
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By roecker Tue Apr 23, 2013 3:59 am
Let us know how it goes.... My 60 has a weak inverter. Just installed a new backlight from saint_baz and its nowhere near as bright as the backlight I installed into my s1000.........
By ZX81 Tue Apr 23, 2013 8:24 pm
I also ordered the inverter that micb recommended in this thread, and a new foil from midi-rakete.de. I hope it will work out alright.
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By Beatdiggerjazzcat Tue Apr 23, 2013 9:33 pm
As I have said to clint in a previous personal conversation

The higher voltage would burn out the el foil very quickly

AND

these USB inverters bleed a high pitched whine into the audio chain as they lack the correct components.

All in all not the best option for people looking for a quick easy fix